U.S. patent number 9,404,634 [Application Number 13/441,571] was granted by the patent office on 2016-08-02 for led light fixture with facilitated lensing alignment and method of manufacture.
This patent grant is currently assigned to Cree, Inc.. The grantee listed for this patent is Craig Raleigh, Christopher Strom, Kurt S. Wilcox. Invention is credited to Craig Raleigh, Christopher Strom, Kurt S. Wilcox.
United States Patent |
9,404,634 |
Wilcox , et al. |
August 2, 2016 |
**Please see images for:
( Certificate of Correction ) ** |
LED light fixture with facilitated lensing alignment and method of
manufacture
Abstract
LED lighting apparatus including (1) a plurality of primary
lenses each over a corresponding one of LED arrays spaced on a
circuit board, and (2) a one-piece lensing member over the circuit
board and having a plurality of secondary lenses each spaced over
one of the primary lenses on the circuit board, the circuit board
and lensing member having first and second mating features
positioned and configured for inter-engagement for high-precision
lens alignment. The circuit board and one-piece lensing member are
each joined to a mounting surface of a heat-conductive member, and
such assembly, while facilitating high-efficiency assembly, does
not interfere with high-precision lens alignment.
Inventors: |
Wilcox; Kurt S. (Libertyville,
IL), Strom; Christopher (Racine, WI), Raleigh; Craig
(Racine, WI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Wilcox; Kurt S.
Strom; Christopher
Raleigh; Craig |
Libertyville
Racine
Racine |
IL
WI
WI |
US
US
US |
|
|
Assignee: |
Cree, Inc. (Durham,
NC)
|
Family
ID: |
47090105 |
Appl.
No.: |
13/441,571 |
Filed: |
April 6, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20120281404 A1 |
Nov 8, 2012 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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12610077 |
Oct 30, 2009 |
8348461 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F21V
31/005 (20130101); F21V 25/12 (20130101); F21V
29/763 (20150115); F21V 5/04 (20130101); F21S
2/005 (20130101); F21V 5/007 (20130101); Y10T
29/49895 (20150115); F21Y 2105/10 (20160801); F21Y
2115/10 (20160801); F21V 7/0008 (20130101); F21W
2131/103 (20130101) |
Current International
Class: |
F21S
4/00 (20160101); F21V 29/76 (20150101); F21V
31/00 (20060101); F21V 25/12 (20060101); F21V
5/04 (20060101); F21V 5/08 (20060101); F21S
2/00 (20160101); F21V 5/00 (20150101); F21V
7/00 (20060101) |
Field of
Search: |
;362/227,240,249.01,249.02,236,237,267,294,373,612,613,800 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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Feb 1996 |
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101315167 |
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Dec 2008 |
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CN |
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202009008928 |
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Aug 2009 |
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DE |
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1413823 |
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Apr 2004 |
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EP |
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2007141585 |
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Jun 2007 |
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JP |
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2007258114 |
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Oct 2007 |
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JP |
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2008103300 |
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May 2008 |
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JP |
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3147703 |
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Dec 2008 |
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JP |
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2009230984 |
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Oct 2009 |
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WO2010011379 |
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Jan 2010 |
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WO |
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Primary Examiner: Sawhney; Hargobind S
Attorney, Agent or Firm: Jansson Munger McKinley & Kirby
Ltd.
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part of currently pending
U.S. application Ser. No. 12/610,077, filed on Oct. 30, 2009.
Claims
The invention claimed is:
1. A method of assembling an LED light fixture, the fixture
including (a) a heat-conductive structure having a mounting
surface, (b) a circuit board having a plurality of LED arrays
spaced thereon with a plurality of primary lenses each over a
corresponding one of the LED arrays and (c) a one-piece lensing
member having a plurality of secondary lenses each positioned to
align with a corresponding one of the primary lenses, the method
comprising: providing a set of mounting holes through the circuit
board and a set of alignment holes in the circuit board; providing
a set of mounting holes through the one-piece lensing member and a
set of alignment protrusions extending from a
circuit-board-adjacent surface of the lensing member; providing
first and second sets of fastener-receiving cavities in the
heat-conductive structure and open at the mounting surface thereof;
mounting the circuit board to the mounting surface by inserting a
first set of fasteners through the circuit-board mounting holes
into the first set of fastener-receiving cavities; aligning the
lensing member with respect to the circuit board by mating
engagement of the alignment protrusions with the alignment holes;
and installing the lensing member over the circuit board by
inserting a second set of fasteners through the lensing-member
mounting holes into the second set of fastener-receiving
cavities.
2. The method of claim 1 wherein the set of alignment protrusions
includes first and second protrusions and the set of alignment
holes includes a first hole complementary in shape to the first
protrusion to fix the position of the lensing member along the
circuit board, and a second hole to receive the second protrusion
and prevent rotation of the lensing member about the first
protrusion.
3. The method of claim 2 wherein the second hole is elongate along
a line extending between the first and second holes thereby to
facilitate the mating engagement.
4. The method of claim 1 wherein the one-piece lensing member has a
peripheral portion extending beyond the edge of the circuit
board.
5. The method of claim 4 wherein the peripheral portion encircles
the circuit board and engages a gasket providing a weathertight
seal around the circuit board.
6. The method of claim 5 wherein: the one-piece lensing member is
of a polymeric material; and compression-limiting inserts are in
each of the holes of the one-piece lensing member.
7. Lighting apparatus comprising: a heat-conductive structure
having a mounting surface and first and second sets of
fastener-receiving cavities; a circuit board having a plurality of
LED arrays spaced thereon with primary lenses each over a
corresponding LED array, the circuit board having a first alignment
feature and a set of mounting holes, the circuit board being
mounted to the heat-conductive structure with fasteners extending
through the mounting holes into the first set of fastener-receiving
cavities; and a one-piece lensing member over the circuit board and
having a second alignment feature, the one-piece lensing member
being secured to the heat-conductive structure with fasteners
inserted into the second set of fastener-receiving cavities through
the lensing-member mounting holes defined in a peripheral portion
extending beyond the edge of the circuit board, the one-piece
lensing member including a plurality of secondary lenses each over
a corresponding one of the primary lenses, the second alignment
feature being in mating engagement with the first alignment
feature, thereby aligning the secondary lenses over their
corresponding primary lenses.
8. The lighting apparatus of claim 7 wherein: the second alignment
feature is a protrusion extending from a circuit-board-adjacent
surface of the one-piece lensing member; and the first alignment
feature is a complementary hole formed in an LED-supporting surface
of the circuit board.
9. Lighting apparatus comprising: a plurality of LED emitters
spaced on a circuit board; a lensing member over the circuit board
and including a plurality of secondary lenses each spaced over a
corresponding one of the LED emitters, the lensing member including
first and second lens-alignment features which are one of
protrusions and hollows of a circuit-board-adjacent surface; and
the circuit board defining a first board-alignment feature which is
one of a hole and a protrusion defined by an LED-supporting surface
of the circuit board and being complementary in shape to with the
first lens-alignment feature for mating engagement therebetween to
fix the position of the lensing member along the circuit board, and
a second board-alignment feature which is one of a hole and a
protrusion for engagement with the second lens-alignment feature to
prevent rotation of the lensing member about the first
lens-alignment feature.
10. The lighting apparatus of claim 9 wherein: the first and second
lens-alignment features are protrusions; and the first
board-alignment features is a hole complementary in shape to the
first lens-alignment protrusion; and the second board-alignment
feature is a hole elongate along a line extending between the first
and second holes thereby to facilitate mating engagement of the
first lens-alignment feature with the first board-alignment
features.
11. The lighting apparatus of claim 9 further including a
heat-conductive structure having a mounting surface and having
first and second sets of fastener-receiving cavities, the circuit
board being mounted to the heat-conductive structure with fasteners
extending through mounting holes in the circuit board into the
first set of fastener-receiving cavities.
12. The lighting apparatus of claim 11 wherein the one-piece
lensing member is secured to the heat-conductive structure with
fasteners inserted through holes in the one-piece lensing member
into the second set of fastener-receiving cavities.
13. The lighting apparatus of claim 12 wherein: the one-piece
lensing member is of a polymeric material; and compression-limiting
inserts are in each of the holes of the one-piece lensing
member.
14. Lighting apparatus comprising: a plurality of LED light sources
spaced on a circuit board; a one-piece lensing member over the
circuit board and including a plurality of lenses each spaced over
a corresponding one of the LED light sources, the lensing member
having first and second protrusions extending from a
circuit-board-adjacent surface; and the circuit board defining (i)
a first hole complementary in shape to the first protrusion to fix
the position of the lensing member along the circuit board and (ii)
a second hole receiving the second protrusion to prevent rotation
of the lensing member about the first protrusion.
15. The lighting apparatus of claim 14 wherein the second hole is
elongate along a line extending between the first and second holes
thereby to facilitate engagement of the mating features.
16. The lighting apparatus of claim 14 wherein each LED light
source includes an array of LEDs.
17. The lighting apparatus of claim 16 wherein each light source
includes a primary lens over the LED array.
18. The lighting apparatus of claim 17 wherein each of the primary
lenses is overmolded on one of the LED arrays.
Description
FIELD OF THE INVENTION
This invention relates generally to the field of LED light fixtures
and, more particularly, to the field of LED light fixtures for
various high-luminance area lighting applications such as roadway
lighting, factory lighting, parking lot lighting, commercial
building lighting, and the like, and to the manufacture
thereof.
BACKGROUND OF THE INVENTION
In recent years, the use of light-emitting diodes (LEDs) in
development of light fixtures for various common lighting purposes
has increased, and this trend has accelerated as advances have been
made in the field. Indeed, lighting applications which previously
had typically been served by fixtures using what are known as
high-intensity discharge (HID) lamps are now being served by LED
light fixtures. Such lighting applications include, among a good
many others, roadway lighting, factory lighting, parking lot
lighting, and commercial building lighting.
In many of such products, achieving high levels of illumination
over large areas with specific light-distribution requirements is
particularly important. One example is fixtures for roadway
lighting, an application in which the fixtures are generally placed
along roadway edges while light distribution is desired along a
significant portion of roadway length and, of course, on the
roadway itself--generally to the exclusion of significant light off
the roadway. And in such situations it is desirable to minimize the
use of large complex reflectors and/or varying orientations of
multiple light sources to achieve desired illumination
patterns.
Achieving appropriate light distribution while avoiding or
minimizing the use of complex reflectors and/or varying
orientations of multiple light sources requires the use of lens
systems for that purpose. And, where lens alignment plays a role in
lens systems, maximizing their effectiveness requires high
precision in lens alignment.
At the same time, it must be recognized that what is involved in
manufacture of LED light fixtures for roadway illumination and the
like is mass, preferably highly efficient, manufacture of light
fixtures, rather than manufacture of extremely high-cost precision
instruments such as for laboratory usage or the like. More
specifically, it is of great importance that the economics of
low-cost, high-efficiency manufacture be satisfied, but while still
achieving the high-precision lens alignment necessary to maximize
performance of high-luminance LED light fixtures for roadway
illumination and the like.
SUMMARY OF THE INVENTION
The present invention is an improved LED light fixture with
high-precision lens alignment, and a high-efficiency manufacturing
method for such LED light fixture.
The method of this invention is a method of assembling an LED light
fixture of the sort including (a) a heat-conductive structure
having a mounting surface, (b) a circuit board having a plurality
of LED arrays spaced thereon with a plurality of primary lenses
each over a corresponding one of the LED arrays and (c) a one-piece
lensing member having a plurality of secondary lenses each
positioned to align with a corresponding one of the primary lenses.
The inventive method includes: providing a set of mounting holes
through the circuit board and a set of alignment holes in the
circuit board; providing a set of mounting holes through the
one-piece lensing member and a set of alignment protrusions
extending from a circuit-board-adjacent surface of the lensing
member; providing first and second sets of fastener-receiving
cavities in the heat-conductive structure and open at the mounting
surface thereof; mounting the circuit board to the mounting surface
by inserting a first set of fasteners through the circuit-board
mounting holes into the first set of fastener-receiving cavities;
aligning the lensing member with respect to the circuit board by
mating engagement of the alignment protrusions with the alignment
holes; and installing the lensing member over the circuit board by
inserting a second set of fasteners through the lensing-member
mounting holes into the second set of fastener-receiving
cavities.
The lighting apparatus of this invention includes: (1) a plurality
of primary lenses each over a corresponding LED array, the LED
arrays spaced on a circuit board, the circuit board having a first
mating feature; and (2) a one-piece lensing member over the circuit
board, the circuit board including a plurality of secondary lenses
each spaced over a corresponding one of the primary lenses, the
one-piece lensing member having a second mating feature positioned
and configured for mating engagement with the first mating feature,
the first and second mating features engaged to accurately align
the secondary lenses over their corresponding primary lenses.
In some embodiments, the second mating feature is a protrusion
extending from a circuit-board-adjacent surface of the one-piece
lensing member, and the first mating feature is a complementary
hole formed in an LED-supporting surface of the circuit board. In
such embodiments, the lensing member may have first and second
protrusions extending from its circuit-board-adjacent surface, and
the circuit board defines (a) a first hole complementary in shape
to the first protrusion to fix the position of the lensing member
along the circuit board and (b) a second hole receiving the second
protrusion to prevent rotation of the lensing member about the
first protrusion. The second hole may be elongate along a line
extending between the first and second holes to facilitate
engagement of the mating features.
Certain embodiments of the present invention also include the
heat-conductive structure including a mounting surface to which the
circuit board and the lensing member are secured. The
heat-conductive structure has first and second sets of
fastener-receiving cavities open at the mounting surface. The
circuit board is mounted to the heat-conductive structure with
fasteners extending through mounting holes in the circuit board and
into the first set of fastener-receiving cavities. The one-piece
lensing member is secured to the heat-conductive structure by
fasteners inserted through holes in the one-piece lensing member
and into the second set of fastener-receiving cavities.
The one-piece lensing member may have a peripheral portion
extending beyond the edge of the circuit board. Such peripheral
portion preferably encircles the circuit board and engages a gasket
providing a weathertight seal around the circuit board. The
one-piece lensing member may be of a polymeric material, and
compression-limiting inserts are in each of the holes of the
one-piece lensing member.
Precise alignment of lenses give the full light-distribution
benefits that are intended is achieved by this invention, while
still allowing highly-efficient assembly.
In descriptions of this invention, including in the claims below,
the terms "comprising," "including" and "having" (each in their
various forms) and the term "with" are each to be understood as
being open-ended, rather than limiting, terms.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded bottom perspective view of an LED light
fixture according to the present invention.
FIG. 2 is a plan view of a circuit board.
FIG. 3 is a plan view of a one-piece lensing member.
FIG. 4 is a perspective view of the lensing member of FIG. 3.
FIG. 5 is a perspective view of the lensing member of FIG. 3
aligned over the circuit board.
FIG. 6 is a plan view of a mounting surface of a heat-conductive
structure.
FIG. 7 is a perspective view showing the circuit board mounted to
the heat-conductive structure.
FIG. 8 is a perspective view showing the lensing member aligned
over the circuit board mounted to the heat-conductive
structure.
FIG. 9 is a perspective view showing the lensing member installed
to the heat-conductive structure.
FIG. 10 is a perspective sectional view across the heat-conductive
structure and showing securement of the one-piece lensing member to
the heat-conductive structure.
FIG. 11 is a perspective sectional view across the heat-conductive
structure and showing mounting of the circuit board to the
heat-conductive structure.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
FIGS. 1-9 illustrate LED light fixture 10 according to the present
invention and a high-efficiency manufacturing method for such LED
light fixture 10 which gives high-precision lens alignment.
FIG. 1-5 best illustrates that LED light fixture 10 includes a
heat-conductive structure 20, a circuit board 30 and a one-piece
lensing member 40. Heat-conductive structure 20 has a mounting
surface 23 best seen in FIGS. 1 and 6. FIGS. 1, 2 and 5 best
illustrate circuit board 30 which has a plurality of LED arrays 31
spaced thereon with a plurality of primary lenses 32 each over a
corresponding one of LED arrays 31. FIGS. 3-5 best show one-piece
lensing member 40 having a plurality of secondary lenses 41 each
positioned to align with a corresponding one of primary lenses
32.
In the inventive method, a set of mounting holes 33 is provided
through circuit board 30 and a set of alignment holes 34 is
provided in the circuit board 30, as best seen in FIG. 2. A set of
mounting holes 42 (best seen in FIG. 3) is also provided through
one-piece lensing member 40. A set of alignment protrusions 43
(best seen in FIGS. 3 and 4) is also provided, protrusions 43
extend from a circuit-board-adjacent surface 44 of lensing member
40. In heat-conductive structure 20, first and second sets of
fastener-receiving cavities 21 and 22.
As seen in FIG. 1, cavities 21 and 22 are open at mounting surface
23 of heat-conductive structure 20. FIGS. 1, 7 and 11 show that
circuit board 30 is mounted to mounting surface 23 by inserting a
first set of fasteners 11 through circuit-board mounting holes 33
into first set of fastener-receiving cavities 21. FIG. 5
illustrates alignment of lensing member 40 with respect to circuit
board 30 by mating engagement of alignment protrusions 43 with
alignment holes 34 such that secondary lenses 41 are accurately
aligned over their corresponding primary lenses 32. FIGS. 1 and 10
show that lensing member 40 is installed over circuit board 30 by
inserting a second set of fasteners 12 through lensing-member
mounting holes 42 into second set of fastener-receiving cavities
22.
It is best seen in FIGS. 3-5 that lensing member 40 has first and
second protrusions 431 and 432 extending from its
circuit-board-adjacent surface 44. FIG. 2 shows that circuit board
30 defines first and second alignment holes 341 and 342. First hole
341 is complementary in shape to first protrusion 431 to fix the
position of lensing member 40 along circuit board 30. And, as seen
in FIG. 5, second hole 342 receives second protrusion 432 to
prevent rotation of lensing member 40 about first protrusion 431.
FIG. 2 further shows second hole 342 elongate along a line 35
extending between first and second holes 341 and 342. This
facilitates engagement of mating features in the form of alignment
holes 34 and protrusions 43.
FIGS. 1, 5, 10 and 11 show that one-piece lensing member 40 has a
peripheral portion 45 extending beyond edge 36 of circuit board 30.
Peripheral portion 45 encircles circuit board 30 and engages a
gasket 13 which provides a weathertight seal around circuit board
30. Since one-piece lensing member 40 may be of a polymeric
material, compression-limiting inserts 46 in such embodiments are
used in each of mounting holes 42 of one-piece lensing member
40.
While the principles of the invention have been shown and described
in connection with specific embodiments, it is to be understood
that such embodiments are by way of example and are not
limiting.
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